Autostart an Operator from custom node
To achieve this I wrote an operator that inserts the node in the NodeTree sets it active and starts the associated Operator
import bpy

class SFX_OT_IN_Adder(bpy.types.Operator):
    &quot;&quot;&quot; Insert a Clock Node to the Node Tree and start it&quot;&quot;&quot;
    bl_idname = &quot;sfx.in_clock&quot;
    bl_label = &quot;Insert Adder Node&quot;

def invoke(self, context, event):
    node_tree = bpy.context.space_data.edit_tree.name
    Node = bpy.data.node_groups[node_tree].nodes.new('SFX_ClockNode')
    bpy.data.node_groups[node_tree].nodes.active = Node
    bpy.ops.sfx.clockstartop('INVOKE_DEFAULT')
    return {'FINISHED'}

def draw(self,context):
    pass

and put it in the node_menu
layout.operator('sfx.in_clock', text = 'Clock', icon = &quot;CURVE_NCIRCLE&quot; )